Motor-controlling device.



J. P. TARBOX. MOTOR CONTROLLING DEVICE.

APPLICATION FILED JUNE 30,1908. 7

Patented Apr. 6," 1909.

IIIIII m mentor,

Mness'es/ M613 I? mmw JOHhI P. TARBOX, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOB. TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MOTOR*CONTROLLING DEVICE.

Specification of Letters Patent.

Patented April 6, 19cc.

' Application filed June 30, 1908. Serial No. 441,066.

To all whom it may concern:

Be it known that I, JOHN P. -TARBOX, a citizen of the United States, residing at \Vashington, District of Columbia, have invented .certain new and useful Improvements in Motor-Controlling Devices, of which the following is a specification.

This invention relates to devices for controlling electric circuits and has for its object the provision of motor may be stopped, started and generally controlled in a re iable, simple and efiicient manner.

My invention relates more specifically to starting devices for electric motors, one of my objects being to provide a starting rheostat with means whereby the motor circuit may be automatically controlled in response to variations in speed or load conditions.

While my invention is capable of wide and varied applications I regard it as of articular importance in connection with ioisting mechanism and the like. In this class. of apparatus the motor is often stalled by heavy loads, and it becomes necessary therefore to protect the motor under these conditions,

In carrying out my invention I combine with a starting rheostat, automatic regulating features so that the operating mechanism is used for both starting and regulating. The motor is brought up to running speed by hand whereupon the controlling member is released so that upon change in seed or load conditions, the arm may be shi ted accordin ly.

In the accompanying drawing in which I have shown my invention embodied in concrete form, Figure 1 is a plan view of a combined starting and controlling rheostat embodying my invention and rig. 2 is a detail View showing the mounting for the operating and controlling members.

Referring to the drawing, 10 is an ordinary panel board or base of some insulating material, such as slate or soapstone, having mounted thereon a seriesof contact studs 11 forming terminals of starting resistance 12. lVhile I.

refer to this resistance as starting resistance,

, it is nevertheless of such a. nature that it will 16 which extends beyond the pivota carry current for an indefinite period and may therefore be used for regulating the speed of the motor. is pivoted at 14 so that its free end engages the studs 11. The arm 13 has a projection means whereby an electric A controlling member or arm 13 projection at 18 and the other end fixed to the central stud gives the arm '13 a bias' in a clockwise direction or toward the running position. This arm 13 is arranged to be 0 erated automatically in response to varia tions in the load or speed of the motor.

For pur a series so enoid 19 as the operating agency. This solenoid is mounted-upon the base as shown and its core 20 is connected with the projection 16 by means of a link 21. The ar rangement is such that upon a predetermined increase in current, the core 20will be drawn in so as to move the arm 13 in a counterclockwise direction while, when the current again decreases, the spring 17 will op' crate to withdraw the core and move the arm in a clockwise direction ically regulating the speed of the motor and An operating arm ally with the arm 13 upon the stud 1.4 so as to move independently thereof. This arm is provided with an operating handle 23 and is iased to the oif position shown in the drawing by means of the spring 24. Ihis spring is stiffer than the spring 17. The arm 22 is provided with a pro ection which engages the arm 13, and the spring 24 is of suflicient strength to force the arm 22 and the arm 13 to the oii position thereby overcoming the tension of the spring 17 as well as the effect of the solenoid 19. A latch 25 is pivoted upon the arm 22 and has" one end pro ecting over a pin 26 upon the arm 13 so as to lock the two arms together. The opposite end of the as to engage the pin 28 when the arm reac running position and move the latch to release the arm. 13. A no-voltage magnet 29 is located in the usual place so as to hold the arm 22 in running position.

'lhe arrangement of circuits and mode of operation are as follows: When it is desired to start the motor, the arm 23 is grasped and since the two members 13 and 22 are locked together they will both move to the running position thereby bringing the motor up to running speed. When the arm 22 reaches running position it is held by the magnet 29. At the same time the finger 27 engages the pin 28 and releases the arm 13. This arm 13 eing relieved of the tension of spring 24 will point 1 not be returned to the off position but will be protecting it against dangerous overloads. 22 1S pivoted concentr1c-' latch is in the shape of a linger 27 so wrangledes and a spring17 having one end fixed to the oses of illustration I have shown I thereby automatlit controlled by the solenoid 19. When the load on the motor becomes heavy the arm 13 will be moved in a counter-clockwise direction so as to insert resistance in the armature circuit to protect the motor. W'hen the load is relieved the spring 17 will move the arm so as to cut out the resistance. Jpon the fail-. ure of voltage the arm 22 will be released by the retaining magnet and will retprn to the off position, carrying with it the arm 13, the two arms thereupon being automatically latched together.

While I have shown my invention in connection with actuating mechanism arranged to operate in a definite way, it should be understood that this is done merely for pur poses of illustration since various modifications of my invention will suggest themselves to those skilled in the art Without de parting from the spirit of my invention, the scope of which is set forth in the annexed claims. 7

WVhat I claim as new and desire to secure by Letters Patent of the United States, is:

1. A rheostat comprising a starting resistance, a controlling member therefor, means responsive to variations in load conditions of the-motor for automatically shifting said member to vary the resistance, and an operating member having a bias to starting position arranged to move the controlling member in the direction of the bias.

2. I A rheostat comprising a starting resistance, a controlling-membertherefor, an.

electromagnetic device responsive to variations in the motor tor automatically shifting said member to vary the resistance, and an operating member having a bias to starting position arranged to move the controllmg member in the direction of the bias.

3. A rheostat comprising a starting resistance, a controlling member therefor,

means for automatically shifting said memher to vary the resistance. in response to variations in the speed ofthe motor, and means for giving said member a bias toward starting position sufficient to overcome the shifting means until the running position is reached and then removing said bias.

4. A rheostat comprising a starting resistance, a controlling member therefor, means responsive to variations in the load conditions of the motor for automatically shifting said member to vary the resistance, an operating member having a bias to starting position arranged to normally press the controlling member in the direction of the bias, and a no 'voltage magnet for holding the operating member in running position. 5. A rheostat comprising a starting resistance,a controlling member therefor, an electromagnetic device responsive to changes in the motor current for automatically shifting said member to vary the resistance, an operating member mounted to give the con- !reached and then releasing the controlling l member.

6. A rheostat comprising a starting re 1 sis'tance, a controlling member therefor, means responsive to current variations in the motor for automatically shifting said member to vary the resistance, an operating memlber locked to the controlling member and having a bias sufficient to move both members to starting position, a lie-voltage mag net, and means for unlocking said members and releasing the controlling member when running position is reached.

7. A rheostat comprising a starting resistance, a controlling member therefor, a solenoid incircuit with the motor arranged to shift said member in response to variations of the motor current, and an operating I member having, a bias to starting position and in engaging relation with the controlling member so as to move it in the direction of the bias.

8. A rheos'tat comprising a starting resistance, a controlling"member therefor, a solenoid in circuit with. the motor arranged to shift said member in response to variations of the motor current, an operating member having a bias to starting position latched to the controlling member, a Ito-voltage magnet, and means for unlatching said members and releasing the controlling member when the operating member engages the magnet.

9. A rheostat comprising a starting resistance, a controlling member therefor having a bias to running position, a solenoid for moving said member to starting position, an operating member mounted to give the controlling member a bias to starting position sufficient to move' the controlling member against its own bias, a no-voltage magnet, and means whereby said members are caused to move together until the magnet is reached and then the controlling member is released.

10. A rheostat comprising a starting reing a bias to running position,- .a solenoid to move said member to starting osition, an operating member locked to sai controlling member and mounted to give the latter a bias to starting position sufficient to move it against its own bias, a no-voltage magnet for holding the operating member in running sistance, a controlling member thereforhavposition, and means whereby said members 

